Subterranean emergency shelter

ABSTRACT

In one embodiment, a shelter includes a base with an interior chamber defined by a bottom wall, a sidewall, and an open upper end. A closure is joined to the base to enclose the chamber. A passageway through the closure facilitates entry into the chamber and exit from the chamber. Rungs disposed in the chamber extend through the passageway to define a stairway. The shelter may also include a door coupled to the passageway. The door can be moved from a closed position covering the passageway to an open position away from the passageway.

This application claims priority to pending U.S. Provisional Patent Application No. 60/886,206, filed Jan. 23, 2007, which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention relates generally to protective shelter structures, and more particularly to a subterranean tornado shelter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention in sufficient detail to enable one of ordinary skill in the art to which the invention pertains to make and use the invention.

FIG. 1 is a perspective view of an exemplary shelter in accordance with the principles of the present disclosure.

FIG. 2 is an exploded perspective view of the shelter of FIG. 1.

FIG. 3 is a perspective view of the shelter of FIG. 1, installed beneath the ground.

FIG. 4 is a cross-sectional view of the shelter of FIG. 3, taken along line 4-4.

FIG. 5 is a cross-sectional view of the shelter of FIG. 3, taken along line 5-5.

FIG. 6 is a detailed cross-section of the encircled area of FIG. 5, illustrating an alternative embodiment.

DETAILED DESCRIPTION

FIGS. 1 through 5 depict an exemplary subterranean emergency shelter 10. The shelter 10 comprises a base 12 having an interior chamber 14 defined by a bottom wall 16, at least one chamber sidewall 18 extending upwardly from the bottom wall 16, and an open upper first end 20. In the embodiment shown, the base 12 is rotationally molded from polymeric material and has a double wall construction, wherein the inner wall surfaces 22 define the chamber 14 of the base 12 and the outer wall surfaces 24 define the exterior of the base 12, as depicted in FIGS. 4-5. Between the inner and outer walls 22, 24 is a void or cavity 26 which may be filled with air or, alternatively, an insulative or ballast material 28. In one embodiment, a ballast material 28 in the cavity 26 may be water.

The shelter 10 may be moved to an installation site without ballast material 28 in the cavity 26, and may be placed in a desired location that has been excavated to accommodate the shelter 10. Thereafter, the cavity 26 may be filled with an insulative or ballast material 28. Accordingly, the unfilled cavity 26 minimizes the weight of the shelter 10 and facilitates transportation and handling of the shelter 10 prior to installation.

In the embodiment shown, the exterior surface of the base 12 comprises a first portion 30 having a generally frustoconical shape that gradually becomes wider in a direction from the open upper end 20 of the base 12 toward the lower end 32 of the base 12. A second portion 34 of the exterior surface extends radially, outwardly from the first frustoconical portion 30 and has the general shape of an oblique rectangular prism which extends from the lower end 32 of the base 12 to the open upper end 20. The exterior surface of the base 12 includes a plurality of ribs 36 extending generally from the lower end 32 of the base 12 toward the open upper end 20. The ribs 36 are spaced apart circumferentially around the perimeter of the base 12 and define pockets 38 therebetween. The arrangement of ribs 36 and pockets 38 helps to strengthen the structure of the base 12, and the sloped exterior walls help to anchor the base 12 below the ground surface 40 (FIG. 3).

Referring to FIGS. 4-5, the inner wall surfaces 22 of the base 12 define the chamber 14. In the embodiment shown, the chamber 14 includes a seat structure 42 that is integrally formed with the chamber sidewalls 18. In this embodiment, the seat structure 42 extends along the circumference of the chamber sidewall 18 and has a generally annular configuration. The chamber 14 further includes a recess 44 extending radially outwardly in the region of the second portion 34 of the base 12 and having the general form of a rectangular prism. A stairway 46 for entering and exiting the chamber 14 is located at the recess 44, as will be described in more detail below.

The shelter 10 further includes a closure 50 joined to the open upper end 20 of the base 12 to thereby enclose the chamber 14. In the embodiment shown, the closure 50 is rotationally molded from polymeric material and has a double wall construction, similar to that described below for the base 12. To provide strength and rigidity to the structures of the rotationally molded base 12 and closure 50, various portions of the base 12 and closure 50 may be strengthened with “kiss-offs” 52, 54 disposed between oppositely facing walls of the base 12 and/or closure 50, as depicted in FIG. 4. A kiss-off is a term of art that refers to a molded structure formed by bringing spaced, opposing wall surfaces together in a desired area such that the material of the opposed walls is joined or fused together in that area to define a common interface.

The peripheral shape of the closure 50 comprises a generally circular portion 56 and a generally rectangular portion 58 extending generally radially therefrom, to correspond to the open upper end 20 of the base 12. The closure 50 may include ribs 55 or other structure to provide strength and resist deformation under load. The closure 50 may be joined to the open upper end 20 of the base 12, for example, by extrusion welding, joining with adhesive or fasteners, or by any other method suitable for coupling the closure 50 to the open upper end 20 of the base 12.

Referring to FIGS. 2-4, a passageway 60 extends through the closure 50 adjacent the generally rectangular portion 58 and is sized to facilitate entry into and exit from the chamber 14. In the embodiment shown, the passageway 60 comprises upper walls 62 a, 62 b, 62 c, 62 d extending generally upwardly from the top surface 64 of the closure 50. In this configuration, the entire shelter 10, including the base 12 and top surface 64 of the closure 50 may be buried below grade, with only the upper portion of the passageway 60 extending above the ground surface 40, as depicted in FIG. 3.

The shelter 10 further includes a door assembly 70 coupled to the passageway 60, generally at the upper edge 72 of the upper walls 62 a, 62 b, 62 c, 62 d. The door assembly 70 comprises a generally rectangular doorframe 74 which may be secured to the upper edge 72 of the passageway 60. A door 76 is hingedly coupled to the doorframe 74 and can be moved between a closed position (FIG. 1) wherein the door 76 covers the entire passageway 60, and an open position away from the passageway 60 (FIGS. 2-5) to permit entry into or exit from the chamber 14 through the passageway 60. In the embodiment shown, the door assembly 70 includes one or more cylinders 78, with extensible rods 78 a, to control movement of the door 76 between the open and closed positions. As seen in FIG. 4, each cylinder 78 is coupled at a first end 80 to the doorframe 74, and at a second end 82 to the door 76. In the embodiment shown, the door 76 includes oppositely disposed flange plates 84 a, 84 b on the side of the door 76 that faces the chamber 14 in the closed position. The second ends 82 of the cylinders 78 are coupled to the flange plates 84 a, 84 b. The cylinders 78 may be configured to lock the door 76 in at least one of the open position or closed position of the door 76.

With reference to FIG. 5, the closure 50 further includes at least one vent 90 a, 90 b through the closure 50 and communicating with chamber 14. Vents 90 a, 90 b provide a flow of fresh air into the chamber 14 and help to circulate air from the chamber 14. When the shelter 10 is installed below grade, vent pipes 92 may be coupled to the vents 90 a, 90 b to extend above the ground level 40. In one embodiment, the shelter 10 may include a circulating air fan 94 disposed in one of the vents 90 a, 90 b, or otherwise cooperating with one of the vents 90 a, 90 b, to draw fresh air in from outside the chamber 14 and to force air in the chamber 14 out through an oppositely positioned vent. The fan 94 may be powered by a battery, solar power, or various other power sources or combinations thereof (not shown).

The shelter 10 further includes a stairway 46 extending from the chamber 14 and through the passageway 60 to facilitate entering the chamber 14 and exiting the chamber 14 through the passageway 60. In the embodiment shown, the stairway 46 comprises ladder-type structure including a plurality of rungs 100 spaced apart in a vertical direction and extending from the chamber 14 upwardly through the passageway 60. The rungs 100 are supported in the chamber 14 by generally vertically extending chamber stringers 110 a, 110 b that are integrally formed with the chamber sidewalls 18. As seen in FIGS. 4-5, the chamber stringers 110 a, 110 b are located on oppositely disposed chamber sidewalls 18 within the protruding second portion 34 of the base 12 and the stringers 110 a, 110 b include notches 112 spaced in a vertical direction. The rungs 100 are received in respectively associated pairs of the notches 112 and may be secured therein, for example, by fasteners or other suitable structure.

The passageway 60 also includes passageway stringers 114 a, 114 b disposed on oppositely facing portions of the upper walls 62 a, 62 c generally above the chamber stringers 110 a, 110 b such that the stairway 46 extends upwardly from the chamber 14 and through the passageway 60. The passageway stringers 114 a, 114 b have pairs of notches 116 for supporting rungs 100 in a generally vertically spaced direction to provide a continuation of rungs 100 from chamber 14.

The door assembly 70 may also include one or more rungs 100 provided on the door 76 such that the stairway 46 extends outwardly from the passageway 60 when the door 76 is in the open position. In this embodiment, the rungs 100 are secured to the door flanges 84 a, 84 b and are spaced apart in a generally vertical direction to provide a continuation of the rungs 100 from the passageway 60. Accordingly, the door 76 may be moved to the open position and locked in place with the cylinders 78, for example, whereby persons may enter or exit the chamber 14 using the rungs 100 provided in the chamber 14 and passageway 60, and on the door 76.

Behind the rungs 100 of stairway 46 and within the recess 44 defined by the protruding rectangular prism portion 34 of the base 12 is a space 120. This space 120 may be used as a storage area for tools, equipment, or provisions for persons using the shelter 10 during an emergency, such as during a tornado.

Referring now to FIGS. 5 and 6, the shelter may further include a faucet 126 within the chamber 14 and extending through a chamber sidewall 18. Faucet 126 provides fluid communication between the chamber 14 and the cavity 26 that is located between the inner and outer walls 22, 24 of the base 12. In the embodiment shown, the faucet 126 includes a spigot 128 communicating with the cavity 26 and a manually adjustable knob 130 for controlling the flow through the spigot 128, whereby liquid ballast material 28 stored in the cavity 26 may be withdrawn through the spigot 128. When the ballast material 28 is water, the faucet 126 may be used to draw water from the cavity 26 for use by occupants of the shelter 10.

While the present invention has been illustrated by the description of an embodiment thereof, and while the embodiment has been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of the general inventive concept. 

1. A subterranean shelter, comprising: a base including a chamber defined by a bottom wall, at least one chamber sidewall extending upwardly from said bottom wall, and an open upper end; a closure joined to said open upper end of said base to thereby enclose said chamber; a passageway through said closure adapted to facilitate entry into said chamber or exit from said chamber; pairs of oppositely disposed notches in said chamber and said passageway through said closure, said pairs of notches spaced in a vertical direction and extending through said passageway; and rungs supported by said respective pairs of notches to define a stairway extending from said chamber through said passage.
 2. The shelter of claim 1, further comprising a door coupled to said passageway, said door having a closed position covering said passageway, and an open position to permit entry into said chamber or exit from said chamber through said passageway.
 3. The shelter of claim 2, further comprising: at least one rung on said door and cooperating with said rungs supported by said notches in said chamber and said passageway such that said stairway is extended outwardly of said passageway when said door is in said open position.
 4. The shelter of claim 1, wherein said base has an exterior surface comprising a first portion with a generally frustoconical shape that widens in a direction from said open upper end of said base toward a lower end of said base proximate said bottom wall, and a second portion extending radially outwardly from said first portion, said second portion having the shape of an oblique rectangular prism extending from said lower end of said base to said closure.
 5. The shelter of claim 4, further comprising a plurality of ribs formed on said exterior surface.
 6. The shelter of claim 1, wherein said passageway is defined by upper sidewalls extending vertically upwardly from said closure.
 7. The shelter of claim 1, wherein said base is rotationally molded from polymeric material.
 8. The shelter of claim 7, wherein said closure is rotationally molded from polymeric material.
 9. The shelter of claim 8, wherein said notches are integrally molded into said base and said closure
 10. The shelter of claim 1, further comprising a seat in said chamber and integrally formed with said chamber sidewall.
 11. The shelter of claim 1, further comprising at least one vent through said closure and communicating with said chamber.
 12. The shelter of claim 11, further comprising a fan associated with said at least one vent.
 13. A subterranean shelter, comprising: a base including a chamber defined by a bottom wall, at least one sidewall extending upwardly from said bottom wall, and an open upper end; a closure joined to said open upper end of said base to thereby enclose said chamber; a passageway through said closure adapted to facilitate entry into said chamber or exit from said chamber; said base having a double-wall construction comprising an outer wall and an inner wall separated by an interior cavity; and fluid ballast material disposed in said interior cavity.
 14. The shelter of claim 13, wherein said fluid ballast material is water.
 15. A subterranean shelter, comprising: a base including a chamber defined by a bottom wall, at least one sidewall extending upwardly from said bottom wall, and an open upper end; a closure joined to said open upper end of said base to thereby enclose said chamber; a passageway through said closure adapted to facilitate entry into said chamber or exit from said chamber; said base having a double-wall construction comprising an outer wall and an inner wall separated by an interior cavity; and a faucet within said chamber and communicating with said interior cavity, said faucet operative to facilitate the withdrawal of fluid material stored in said interior cavity. 